How to test engine compression?
STEP 1 Remove the fuel pump and fuel-injection fuses. Disconnect the main wire to the coil and spark plug wires; remove spark plugs. STEP 2 Start the threaded end of the compression gauge in a spark plug hole by hand. STEP 3 Turn the ignition on, depress the throttle, and crank the engine four revolutions.
What is a compression test?
The compression test works by spinning the engine through its cycles with the compression tester in place of the spark plug in the cylinder. As the engine makes pressure, the gauge will move and hold to the highest point read by the gauge. Take measurements for all cylinders and then compare the readings to each other.
Will an engine run with 90 psi compression?
They shouldn’t vary more than 10% from highest to lowest. That all said, 90 psi is too low, even for a low compression engine.
What causes the p0302 code on a VW Beetle?
There are quite a few things that can cause the P0302 trouble code to trigger the Volkswagen Beetle . Here are the most common problems that will throw the code. They are presented somewhat in order from most to least likely to be causing the code: Bad Spark Plugs – Spark plugs are one of the most common causes of P0302.
Why does my Volkswagen Beetle have a misfire code?
Driving with a misfire can damage that catalytic converter. Raw fuel is also passing through the cylinder into the exhaust. Mileage may suffer as well when your Beetle has P0302. P0302 is a cylinder specific misfire code, which means that cylinder 2 is misfiring and causing the code.
What happens if you misfire the p0302 cylinder?
Fixing P0302 should be a high priority. Unlike a lot of the OBDII codes, this code has to do directly with engine combustion. Driving with a misfire can damage that catalytic converter. Raw fuel is also passing through the cylinder into the exhaust. Mileage may suffer as well when your Beetle has P0302.
How do you test the compression of an engine?
Avoid any flames around the engine during the test. First of all, connect the tester to a cylinder and turn the engine over 6 to 8 compression strokes. You will be able to hear the cranking speed slow; as the tested cylinder comes up on it’s compression stroke. Note how fast the compression increases and write down the highest reading.